From 362f2cc97745690ff4739b530f5ba95aea59be09 Mon Sep 17 00:00:00 2001 From: Euler Taveira Date: Fri, 9 Mar 2018 17:37:36 +0000 Subject: [PATCH v2 2/9] Store number of tuples in WalRcvExecResult It seems to be a useful information while allocating memory for queries that returns more than one row. It reduces memory allocation for initial table synchronization. While in it, since we have the number of columns, allocate only nfields for cstrs instead of MaxTupleAttributeNumber. --- .../replication/libpqwalreceiver/libpqwalreceiver.c | 9 ++++++--- src/backend/replication/logical/tablesync.c | 5 ++--- src/include/replication/walreceiver.h | 1 + 3 files changed, 9 insertions(+), 6 deletions(-) diff --git a/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c b/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c index 6eba08a920..846b6f89f1 100644 --- a/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c +++ b/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c @@ -878,6 +878,7 @@ libpqrcv_processTuples(PGresult *pgres, WalRcvExecResult *walres, errdetail("Expected %d fields, got %d fields.", nRetTypes, nfields))); + walres->ntuples = PQntuples(pgres); walres->tuplestore = tuplestore_begin_heap(true, false, work_mem); /* Create tuple descriptor corresponding to expected result. */ @@ -888,7 +889,7 @@ libpqrcv_processTuples(PGresult *pgres, WalRcvExecResult *walres, attinmeta = TupleDescGetAttInMetadata(walres->tupledesc); /* No point in doing more here if there were no tuples returned. */ - if (PQntuples(pgres) == 0) + if (walres->ntuples == 0) return; /* Create temporary context for local allocations. */ @@ -897,15 +898,17 @@ libpqrcv_processTuples(PGresult *pgres, WalRcvExecResult *walres, ALLOCSET_DEFAULT_SIZES); /* Process returned rows. */ - for (tupn = 0; tupn < PQntuples(pgres); tupn++) + for (tupn = 0; tupn < walres->ntuples; tupn++) { - char *cstrs[MaxTupleAttributeNumber]; + char **cstrs; ProcessWalRcvInterrupts(); /* Do the allocations in temporary context. */ oldcontext = MemoryContextSwitchTo(rowcontext); + cstrs = palloc(nfields * sizeof(char *)); + /* * Fill cstrs with null-terminated strings of column values. */ diff --git a/src/backend/replication/logical/tablesync.c b/src/backend/replication/logical/tablesync.c index 0a565dd837..42db4ada9e 100644 --- a/src/backend/replication/logical/tablesync.c +++ b/src/backend/replication/logical/tablesync.c @@ -709,9 +709,8 @@ fetch_remote_table_info(char *nspname, char *relname, (errmsg("could not fetch table info for table \"%s.%s\": %s", nspname, relname, res->err))); - /* We don't know the number of rows coming, so allocate enough space. */ - lrel->attnames = palloc0(MaxTupleAttributeNumber * sizeof(char *)); - lrel->atttyps = palloc0(MaxTupleAttributeNumber * sizeof(Oid)); + lrel->attnames = palloc0(res->ntuples * sizeof(char *)); + lrel->atttyps = palloc0(res->ntuples * sizeof(Oid)); lrel->attkeys = NULL; natt = 0; diff --git a/src/include/replication/walreceiver.h b/src/include/replication/walreceiver.h index e12a934966..0d32d598d8 100644 --- a/src/include/replication/walreceiver.h +++ b/src/include/replication/walreceiver.h @@ -196,6 +196,7 @@ typedef struct WalRcvExecResult char *err; Tuplestorestate *tuplestore; TupleDesc tupledesc; + int ntuples; } WalRcvExecResult; /* libpqwalreceiver hooks */ -- 2.19.1